Opening this afternoon's sitting of the Dáil, Sean Ó Fearghaíl criticised the attendees, saying there were serious public health breaches and intelligent people made a decision which was fundamentally wrong.
He confirmed the golfing society was never formally established by the Houses of the Oireachtas and has never received any funding.
Speaking before Dáil business began, Mr Ó Fearghaíl said: "We all make mistakes. There isn't one amongst us who, if they had their time would not change their approach to some issues, or perhaps not engage in certain situations, at all. That is perfectly normal."
But he added: "Seriously indefensible breaches of public health regulations occurred on the 19th of August in Clifden. These breaches are either the result of collective crass stupidity, or arrogant delusion, or both."
He added that the controversy has "damaged public confidence in our public system" claiming that "confidence wasn't in high esteem" to begin with.
He called on TDs to collectively commit to working together to rebuild confidence in the parliamentary system.
"As legislatures, we make the rules but the rules apply to everyone and there are currently no exceptions or special treatment. It must be fairness, consistency and solidarity, as we tackle the scourge of Covid-19," he said.
